WO2022021806A1

WO2022021806A1 - Packaging bag unequal edge defect automatic detection system and method

Info

Publication number: WO2022021806A1
Application number: PCT/CN2021/070241
Authority: WO
Inventors: 冉浩; 陈昌海; 张福; 刘敏; 包成云; 贺军鑫; 张海涛; 杨静; 胡明华; 杨钧; 彭代兵
Original assignee: 冉浩
Priority date: 2020-07-30
Filing date: 2021-01-05
Publication date: 2022-02-03
Also published as: CN114055855A

Abstract

A packaging bag unequal edge defect automatic detection method and system, comprising: first acquiring a packaging bag static state signal used for triggering collection of a packaging bag detection image; then triggering a packaging bag detection image collection device by means of the obtained packaging bag static state signal; acquiring the packaging bag detection image by means of the packaging bag detection image collection device; and finally comparing the collected packaging bag detection image with a standard image to acquire offset of packaging bag sealing edges. In the method, front-back and left-right deviation values of front and back surfaces (or a single surface) of a packaging bag on a packaging bag production line are measured by means of a visual camera, and the front-back or left-right position of the packaging bag on the production line is adjusted by means of a front-back adjustment device or a left-right adjustment device according to the measurement results, thereby achieving the effect of correcting the position deviation of the packaging bag on the production line. The adjustment purpose is to minimize the front-back and left-right deviations of each packaging bag.

Description

Automatic detection system and method for large and small edge defects of packaging bags

technical field

The invention relates to the field of packaging equipment, in particular to an automatic detection system and method for large and small edge defects of packaging bags.

Background technique

Packaging bags can be seen everywhere in our lives. The existing packaging bag production process includes printing patterns on the film to obtain the packaging bag printing film, and then placing the rolled packaging bag printing film on the bag making machine, unwinding the roll to process the packaging bag, During the printing process of the packaging bag, it is necessary to seal the packaging bag. However, during the processing process, the width of the sealing edge on the left and right sides of the packaging bag is often different, and the phenomenon of large and small edges appears, resulting in defective packaging bags. .

At present, whether the size of the sealing edge of the packaging bag meets the production requirements is usually tested manually, which is low in detection efficiency, and prone to missed detection and false detection. required equipment.

SUMMARY OF THE INVENTION

In view of this, the purpose of the present invention is to provide an automatic detection system and method for large and small edge defects of packaging bags, the system has a high degree of automation, is easy to operate, is convenient and efficient, and has reliable functions.

To achieve the above object, the present invention provides the following technical solutions:

A method for automatic detection of the size and edge defects of a packaging bag provided by the present invention comprises the following steps:

Obtain the static state signal of the packaging bag used to trigger the acquisition of the detection image of the packaging bag;

Trigger the packaging bag detection image acquisition device through the obtained static state signal of the packaging bag;

Obtain the detection image of the packaging bag through the packaging bag detection image acquisition device;

The offset of the sealing edge of the packaging bag is obtained by comparing the collected bag inspection image with the standard image.

Further, the following steps are also included:

According to the offset of the sealing edge, it is judged whether the packaging bag exceeds the threshold value of qualified products. If not, the packaging bag is qualified; if it is, the packaging bag is unqualified and rejected.

Further, the offset of the sealing edge of the packaging bag is obtained through the following steps:

Obtain a standard image, and calibrate the distance represented by each pixel in the standard image;

By comparing the current detection image and the standard image, the number of offset pixels in the preset direction is obtained;

The offset of the edge sealing in the preset direction is calculated by the distance represented by each pixel and the number of offset pixels.

Further, the offset of the edge sealing of the packaging bag in the preset direction includes the offset of the bottom edge sealing or the offset of the left and right edge sealing.

Further, the following steps are also included:

The offset is transmitted to an adjustment device for adjusting the position of the packaging bag on the production line, and the position of the packaging bag on the production line is adjusted according to the offset.

Further, the following steps are also included:

The offset of the bottom edge seal is transmitted to the front and rear adjustment device for adjusting the front and rear position of the packaging bag, and the front and rear positions of the packaging bag on the production line are adjusted according to the offset of the bottom edge seal; or

The left and right edge sealing offsets are transmitted to the left and right adjusting device for adjusting the left and right positions of the packaging bags, and the left and right positions of the packaging bags on the production line are adjusted according to the left and right edge sealing offsets.

The present invention also provides an automatic detection system for large and small side defects of packaging bags, comprising a trigger signal generating unit-production line motion sensor, a detection image acquisition unit and a large and small side offset detection device;

The trigger signal generating unit is used for acquiring the static state signal of the packaging bag that triggers the acquisition of the detection image of the packaging bag;

The detection image acquisition unit is used to acquire the detection image of the packaging bag under the triggering control of the static state signal of the packaging bag;

The large and small edge offset detection device is used to obtain the offset of the edge sealing of the packaging bag by comparing the collected detection image of the packaging bag with the standard image.

Further, it also includes a rejecting device; the rejecting device is connected in communication with the large and small side offset detection device, and the large and small side offset detection device obtains the rejection of unqualified products according to the comparison between the offset of the packaging bag and the threshold value of qualified products signal, the rejection signal drives the rejection device to reject the corresponding unqualified products.

Further, the large and small edge offset detection device is provided with a packaging bag edge sealing offset generation unit, and the packaging bag edge sealing offset generation unit obtains the position of the packaging bag in a preset direction by comparing the current detection image and the standard image. offset.

Further, it also includes a packaging bag position adjustment device, the packaging bag position adjustment device is arranged on the production line, the packaging bag position adjustment device is in communication connection with the large and small side offset detection device, and receives the large and small side offset detection device. Send the offset, and adjust the position of the bag on the production line according to the offset.

Further, the packaging bag position adjustment device is a left-right adjustment device, the left-right adjustment device is arranged on the production line, and the left-right adjustment device is connected in communication with the large and small side offset detection device, and receives the large and small side offset detection device. Sent offset, and adjust the left and right position of the bag on the production line according to the offset; or

The packaging bag position adjustment device is a front-rear adjustment device, the front-rear adjustment device is arranged on the production line, the front-rear adjustment device is in communication connection with the large and small side offset detection device, and receives the data sent by the large and small side offset detection device. Offset, and adjust the front and rear position of the packaging bag on the production line according to the offset.

Further, a detection result display device is also included, and the detection result display device is communicatively connected with the large and small side offset detection device, and is used for outputting and displaying the offset of the sealing edge of the packaging bag.

The beneficial effects of the present invention are:

The automatic detection system for the size and edge defects of the packaging bag provided by the present invention detects the front and rear and left and right deviation values of the front and back sides (or single side) of the packaging bag on the packaging bag production line through a visual camera, and adjusts the front and rear adjustment device or the left and right adjustment according to the detection result. The device is used to adjust the front and rear or left and right positions of the packaging bags on the production line to achieve the effect of correcting the position deviation of the packaging bags on the production line. The adjustment goal is to minimize the front and rear and left and right deviations of each packaging bag. According to the test results, it is judged whether the packaging bag has an abnormal size edge and becomes a defective product. The specific method is to compare the preset threshold value in this direction. Generally, if the deviation exceeds the preset threshold value in this direction, it is considered that the size edge abnormality occurs and becomes a secondary product. At this time, the information of unqualified products will be sent to the rejection device of the production line, which will send an alarm signal and automatically reject the unqualified packaging bags.

The detection of big and small sides includes front and rear and left and right directions. No matter which direction the deviation is too large, it will lead to abnormal big and small sides. If the deviation in a certain direction exceeds the maximum allowable deviation in this direction, the packaging bag is considered to be a defective product.

Other advantages, objects, and features of the present invention will be set forth in the description that follows, and will be apparent to those skilled in the art based on a study of the following, to the extent that is taught in the practice of the present invention. The objectives and other advantages of the present invention may be realized and attained by the following description.

Description of drawings

In order to make the purpose, technical solutions and beneficial effects of the present invention clearer, the present invention provides the following drawings for description:

Figure 1 is the flow chart of the automatic detection method for the size and edge defects of the packaging bag

Figure 2 is the structure diagram of the automatic detection system for large and small edge defects of packaging bags.

Figure 3 is a standard unbiased image acquired.

Figure 4 is a detection image of the backward displacement of the packaging bag.

Figure 5 is an inspection image of the bag being shifted backwards and forwards at the same time.

Figure 6 is a detection image of the forward displacement of the packaging bag.

Fig. 7 is a detection image with a shift to the front and the right at the same time.

Fig. 8 is a detected image shifted to the right.

FIG. 9 is a detected image shifted to the left.

FIG. 10 is a comparison effect diagram of detecting image shift by moving forward.

Description of symbols: trigger signal generation unit 1 , detection image acquisition unit, installation device 3 , large and small side offset detection device 4 , detection result display device 5 , left and right adjustment device 6 , and rejection device 7 .

detailed description

The present invention is further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

As shown in Figure 1, the automatic detection method for the size and edge defects of packaging bags provided by this embodiment includes the following steps:

First, obtain the static state signal of the packaging bag on the production line for triggering the acquisition of the detection image of the packaging bag;

When the sensor disposed on the production line detects the static state signal of the packaging bag, the static state signal of the packaging bag is sent to the packaging bag detection image acquisition device as a trigger signal; the packaging bag detection image acquisition device is started to operate, thereby obtaining the packaging bag Detect images.

The static state signal (ie trigger signal) of the packaging bag described in this embodiment is the running state signal of the production line obtained by a photoelectric proximity switch sensor, a laser beam sensor or a laser range finder. Since each packaging bag needs to be divided by a cutter at the end of the production line, when the cutter falls, the packaging bags on the production line near the cutter are in a relatively static state, and the production line running sensor detects the falling of the cutter directly or indirectly. The signal obtains the trigger signal of the camera.

The packaging bag detection image acquisition device provided in this embodiment adopts an industrial camera disposed on the production line, and the detection image is obtained by taking pictures of the industrial camera.

Detecting image requirements: When there is a shift in front and rear or left and right, the image photographing area can clearly reflect this change. Qualified images are: the text pattern or irregular pattern in the middle of the photographing area, the pattern background color is single or other regular colors that are easy to distinguish from the pattern. Unqualified examples are: there is no obvious pattern in the image area, the pattern is a straight line or rectangular area in the front and rear or left and right directions, the background color of the image is disordered, and the pattern is located at the edge of the image, etc.

As shown in Figure 3, Figure 3 is a standard non-offset image collected. This image can be stored as a template image, and then the inspection images collected during the production process of the packaging bag are compared and processed, as shown in Figure 4 , Figure 4 is the detection image of the packaging bag shifting backward; Figure 6 is the detection image that the packaging bag is shifting forward; Figure 5 is the detection image that the packaging bag is offset backward and forward at the same time; from Figure 4 From -6, it can be seen that after comparing with the template image, it is obvious that the offset amount of the forward and backward offset of the packaging bag can be obtained, so as to obtain the adjustment amount that needs to adjust the front and rear offset position of the packaging bag.

In the same way, Figure 7 is the detection image that shifts forward and to the right at the same time, Figure 8 is the detection image that shifts to the right, and Figure 9 is the detection image that shifts to the left. By comparing with the template image, The amount of offset when the packaging bag is offset from left to right or left and right at the same time in the front and back can be obtained, so as to obtain the adjustment amount that needs to be adjusted to the left and right or simultaneous front and rear offset positions of the packaging bag.

Secondly, the collected packaging bag detection image is transmitted to the size edge offset detection device; the position offset of the packaging bag on the production line is obtained through the size edge offset detection device, and the position offset includes the bottom edge sealing Offset and left and right edge sealing offset; in this embodiment, the bottom edge sealing offset and the left and right edge sealing offset are obtained by comparing the detection image of the packaging bag with the standard image. The specific process is as follows:

The obtained standard image is stored as an image template, and the distance represented by each pixel, dx, is calibrated through experiments, and the number of offset pixels between the current detection image and the standard image in the front-back and left-right directions is calculated by the template matching algorithm, which are marked as The number of front and rear offset pixels n1 and the number of left and right offset pixels n2, it should be noted that this number of pixels is a vector with positive and negative directions, specifically defined as front positive and rear negative, left positive and right negative, for example n1=3 Indicates a forward offset of 3 pixels, and n1=-4 indicates a backward offset of 4 pixels; then use n1*dx to get the bottom edge offset, and n2*dx to get the left and right edge offsets.

The comparison method provided in this embodiment is to obtain the pixel value of the deviation after moving the standard picture and compare it with the deviation picture, and then convert it into an offset distance. This method has a fast processing speed and a better effect.

As shown in Figure 10, Figure 10 is a comparison effect diagram of detecting image offset by moving forward. By moving forward the difference between the number of rows and the gray value matrix of the standard image, in the figure, it means that the standard image is moved forward by 10 rows. , 30 lines, 50 lines, 70 lines, 90 lines, 110 lines, 130 lines, 150 lines, 170 lines; and then compared with the collected inspection images, the obtained renderings, when the standard images and inspection images can be completely When canceling, the rendering is that all pixels are completely canceled, resulting in a black picture.

The stored image template is obtained in the following way: after the production line is debugged, the operator manually judges that the offset of the bottom edge sealing and the left and right edge sealing of the current packaging bag are within the preset threshold range. When it is less than the preset threshold, it can be stored in the template library as a standard image.

Then, according to the offset of the bottom edge sealing and the offset of the left and right edge sealing, it is judged whether the packaging bag exceeds the threshold value of qualified products. If not, the packaging bag is a qualified product; The non-conforming product detection signal is sent to the rejection device, and the non-conforming product is rejected.

The automatic detection of the size and edge defects of the packaging bag provided by this embodiment can not only detect the single side of the packaging bag, but also detect both sides of the packaging bag at the same time, and each detection surface of the packaging bag can set a threshold value for qualified products respectively. , that is, four threshold values of front and rear and left and right. At the same time, the specific setting of the threshold value can be determined according to the requirements of different packaging bag products.

Finally, the offset of the bottom edge sealing is transmitted to the front and rear adjustment device, and the position of the packaging bag on the production line is adjusted according to the front and rear offset through the front and rear adjustment device; The left and right adjustment device adjusts the position of the packaging bag on the production line according to the left and right offset;

At the same time, the detected offset of the edge sealing of the packaging bag is output through the display device.

Example 2

As shown in FIG. 2, the automatic detection system for large and small side defects of packaging bags provided in this embodiment includes a trigger signal generation unit, a detection image acquisition unit, an installation device, a large and small side offset detection device, a detection result display device, and a front and rear adjustment device. , Left and right adjustment device, rejection device;

The cover defect detection device is arranged on one side of the rack, and is connected to the cover image acquisition unit in a wired or wireless manner. The cover image acquisition unit is arranged on the rack through the installation device, and the trigger signal generation unit is arranged on the machine. The position on the rack is suitable for judging the movement state of the packaging bag on the rack, the trigger signal generating unit sends the generated signal to the cover image acquisition unit; the cover defect detection device sends the detection result to the detection result display device, the The detection result display device is arranged on one side of the rack or other positions that are easy to observe; the rejecting device is arranged on the rack and is located at the rear end of the cover image acquisition unit, so as to be suitable for the packaging of defective products after the cover image acquisition unit has been acquired The bag is removed; the front and rear adjustment devices or the left and right adjustment devices are respectively arranged on the frame, and realize the adjustment of the position of the packaging bag in the left and right directions and the front and rear directions.

The trigger signal generation unit is used to obtain a trigger signal that triggers the collection of the detection image of the packaging bag, and the trigger signal can be preset as a specific state during the operation of the production line; this state is conducive to collecting the best detection image of the packaging bag, The specific state set in this embodiment is a short-term state in which the cutter set on the production line for cutting the packaging bag just cuts the packaging bag, and the packaging bag is in a stationary state during the period from the drop of the cutter to the completion of the cutting , the detection image of the packaging bag collected during this static time has the best effect. Of course, it can also be judged according to the actual situation. Make the detection image captured just when the packaging bag is in a stationary state.

This embodiment avoids collecting inspection images during the movement of the packaging bag, because the quality of the images collected during the fast moving speed of the packaging bag is poor, or the collected inspection images cannot be accurately positioned, resulting in deformation of the collected packaging bag.

The detection trigger signal in this embodiment is an operation state signal of the production line obtained by a photoelectric proximity switch sensor, a laser beam sensor, or a laser range finder or the like. Set the photoelectric proximity switch sensor at the position close to the cutter, and set the photoelectric proximity switch sensor at the position suitable for installation on the production line through the fixing device.

The detection image acquisition unit is used to collect a preset image area on the packaging bag, the preset image area is photographed by a camera, which can easily identify the position of the packaging bag, so as to analyze whether the position of the packaging bag has changed; this implementation The camera of the example can be an industrial camera. The industrial camera is installed on the production line through the installation device, and the installation device can adjust the installation position of the camera, so that the camera can be conveniently fixed on the production line where the inspection image needs to be collected.

The large and small edge offset detection device is used to obtain the position offset of the packaging bag on the production line; the position offset includes the offset of the bottom edge sealing and the offset of the left and right edge sealing;

The large and small edge offset detection device receives the detection image of the packaging bag, and obtains the offset of the bottom edge sealing and the offset of the left and right edge sealing respectively by comparing the detection image of the packaging bag with the standard image;

The specific process of this embodiment is as follows:

The stored image template is obtained in the following way: after the production line is debugged, the operator manually judges that the offset of the bottom edge sealing and the left and right edge sealing of the current packaging bag are within the preset threshold range. When it is less than the preset threshold, it can be stored in the template library as a standard image. According to the offset of bottom edge sealing and the offset of left and right edge sealing, it is judged whether the packaging bag exceeds the threshold value of qualified products. If not, the packaging bag is qualified; The product detection signal is sent to the rejecting device, and the defective product is rejected.

The large and small side offset detection device provided in this embodiment is a processor that stores the detection image analysis of the packaging bag, and can use a general computer system, a notebook computer or other intelligent devices and devices capable of digital image processing.

The detection result display device is used to output and display the offset of the edge sealing of the packaging bag; the sealing edge of the packaging bag in this embodiment includes left and right edge sealing and bottom edge sealing; The position offset of the packaging bag;

The front and rear adjustment device adjusts the front and rear positions of the packaging bag on the production line by the received offset of the bottom edge sealing;

The left and right adjustment device adjusts the left and right positions of the packaging bag on the production line by receiving the offset of the left and right edge sealing;

This embodiment provides a front-rear adjustment device and a left-right adjustment device, which can use a deviation correction system for adjusting the position in the mechanical device, and adjust the deflection angle through the deviation correction guide roller and the reference guide roller in the deviation correction system. Among them, the front and rear adjustment devices are not marked in the figure.

The rejecting device is used to receive the detection signal of unqualified products that exceeds the threshold value of qualified products sent by the large and small side offset detection device;

The rejection device provided in this embodiment includes a transmission mechanism, a rejection channel, and a rejection mechanism. The rejection passage includes a gap on the transmission mechanism. The rejection mechanism is located above the rejection passage. After the rejection mechanism receives the rejection signal, the packaging bag is rejected from the rejection passage downward. The rejecting mechanism includes a pressing module and/or a guiding module. When the rejecting mechanism receives the rejecting signal, the rejecting mechanism extends downward, the guiding module guides the packaging bag to the rejecting channel, and the pressing module presses down the packaging bag toward the rejecting channel. .

At the same time, a suitable rejecting device can also be selected according to the actual situation, for example, the application number is CN201920918097.2, and the name is the rejecting device described in a mechanical defective rejecting device for sheet materials.

The above-mentioned embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are all within the protection scope of the present invention. The protection scope of the present invention is subject to the claims.

Claims

The automatic detection method for large and small edge defects of packaging bags is characterized by comprising the following steps:

Obtain the static state signal of the packaging bag used to trigger the acquisition of the detection image of the packaging bag;

Trigger the packaging bag detection image acquisition device through the obtained static state signal of the packaging bag;

Obtain the detection image of the packaging bag through the packaging bag detection image acquisition device;

The offset of the sealing edge of the packaging bag is obtained by comparing the collected bag inspection image with the standard image.
The method of claim 1, further comprising the steps of:

According to the offset of the sealing edge, it is judged whether the packaging bag exceeds the threshold value of qualified products. If not, the packaging bag is qualified; if it is, the packaging bag is unqualified and rejected.
The method according to claim 1, wherein the offset of the sealing edge of the packaging bag is obtained by the following steps:

Obtain a standard image, and calibrate the distance represented by each pixel in the standard image;

By comparing the current detection image and the standard image, the number of offset pixels in the preset direction is obtained;

The offset of the edge sealing in the preset direction is calculated by the distance represented by each pixel and the number of offset pixels.
The method according to claim 1, wherein the offset of the sealing edge of the packaging bag in the preset direction includes the offset of the bottom edge sealing or the offset of the left and right edge sealing.
The method of claim 1, further comprising the steps of:

The offset is transmitted to an adjustment device for adjusting the position of the packaging bag on the production line, and the position of the packaging bag on the production line is adjusted according to the offset.
The method of claim 4, further comprising the steps of:

The offset of the bottom edge seal is transmitted to the front and rear adjustment device for adjusting the front and rear position of the packaging bag, and the front and rear positions of the packaging bag on the production line are adjusted according to the offset of the bottom edge seal; or

The left and right edge sealing offsets are transmitted to the left and right adjusting device for adjusting the left and right positions of the packaging bags, and the left and right positions of the packaging bags on the production line are adjusted according to the left and right edge sealing offsets.
An automatic detection system for large and small edge defects of packaging bags, characterized in that: it comprises a trigger signal generating unit (1), a detection image acquisition unit (2) and a large and small edge offset detection device (4);

The trigger signal generating unit (1) is used for acquiring a static state signal of the packaging bag that triggers the acquisition of the detection image of the packaging bag;

The detection image acquisition unit (2) is used to acquire the detection image of the packaging bag under the triggering control of the static state signal of the packaging bag;

The large and small edge offset detection device (4) is used to obtain the offset of the sealing edge of the packaging bag by comparing the collected detection image of the packaging bag with the standard image.
The system according to claim 7, characterized in that: it further comprises a culling device (8); the culling device is connected in communication with the large and small side offset detection device (4), the large and small side offset detection device (4) ) according to the comparison between the offset of the packaging bag and the threshold value of the qualified products to obtain the rejection signal of the non-conforming product, and the rejection signal drives the rejecting device to reject the corresponding non-conforming product.
The system according to claim 7, characterized in that: the large and small side offset detection device (4) is provided with a packaging bag edge sealing offset generation unit, and the packaging bag edge sealing offset generation unit is configured by comparing The current detection image and the standard image get the offset of the packaging bag in the preset direction.
The system according to claim 9, wherein the offset of the sealing edge of the packaging bag in the preset direction includes the offset of the bottom edge sealing or the offset of the left and right edge sealing.
The system according to claim 7, further comprising a packaging bag position adjustment device, the packaging bag position adjustment device is arranged on the production line, and the packaging bag position adjustment device is communicatively connected with the large and small side offset detection device , receive the offset sent by the large and small side offset detection device, and adjust the position of the packaging bag on the production line according to the offset.
The system according to claim 11, characterized in that: the position adjustment device for the packaging bag is a left and right adjustment device (7), the left and right adjustment devices are arranged on the production line, and the left and right adjustment devices detect the offset of the large and small sides. The device is connected in communication, receives the offset sent by the large and small side offset detection device, and adjusts the left and right positions of the packaging bag on the production line according to the offset; or

The packaging bag position adjustment device is a front-rear adjustment device (6), the front-rear adjustment device is arranged on the production line, and the front-rear adjustment device is connected in communication with a large and small side offset detection device, and receives the large and small side offset detection device. The offset sent by the device, and the front and rear positions of the packaging bags on the production line are adjusted according to the offset.
The system according to claim 7, characterized in that: further comprising a detection result display device (5), the detection result display device (5) is connected in communication with the large and small side offset detection device, and is used for outputting and displaying the packaging bag The offset of the edgeband.